Simultaneous enhancements in strength and ductility of hexagonal BN nanosheet reinforced AlSi10Mg composites

We herein report fabrication of hexagonal boron nitride nanosheet (BNNS) reinforced AlSi10Mg composites using a combination of spark plasma sintering (SPS) and hot rolling, the microstructure and mechanical properties of the resulting composites were investigated. The obtained composites present dense microstructure with BNNS uniform distribution. Trace amounts of in-situ interfacial-reaction products such as AlN, AlB2 are observed to endow BNNS-Al interface with good adhesive strength, the interfacial reactions are greatly governed by atom competitive diffusion. In comparison with monolithic AlSi10Mg alloy, the BNNS/AlSi10Mg composites display simultaneous improvements in tensile strength and ductility. In particular, the AlSi10Mg composite with 0.5 wt.% BNNS addition exhibits a yield strength of ~221 MPa and an elongation of ~8.3%, representing enhancements of ~12.7% and ~29.7%, respectively. The possible synergetic strengthening and toughening mechanisms of the resulting composites are discussed based on the test results.